1. Field of the Invention
The invention relates to methods and systems for supporting the evaluation of a picture of an eye.
2. Description of the Prior Art
According to the UK National Screening Committee's (NSC) web site (http://www.diabetic-retinopathy.screening.nhs.uk) approximately 2% of the UK population are known to have diabetes, of whom 200,000 have Type 1 diabetes, and more than a million have type 2 diabetes. This number is expected to increase. It has been estimated that the prevalence of type 2 diabetes in the UK will more than double between 1997 and 2010.
One complication of diabetics is diabetic retinopathy which may affect the blood vessels of the retina. Growth of new blood vessels, known as proliferative retinopathy, may lead to blindness through hemorrhage and scarring. A deterioration of retinal blood vessels causing loss of blood vessels and leakage into the retina is known as maculopathy and leads to visual impairment and may progress to blindness.
Diabetic retinopathy is the biggest single cause of registered blindness in the UK among working age people. Significantly greater numbers suffer visual impairment and handicap due to the effects of diabetic retinopathy. Blindness can cause loss of earning capacity in working age people and required social support is significant, potentially outweighing the costs of prevention and treatment. Diabetic retinopathy can be treated, for instance, by tight glycaemic control and tight blood pressure control. Both treatments reduce the development and progression of diabetic retinopathy in type 1 and type 2 diabetes. In order to be treated, diabetic retinopathy must be diagnosed as soon as possible.
Thus, the need to screen for diabetic retinopathy is uncontroversial. For the screening, images of the eyes of a group of persons who are diagnosed with diabetes are taken and subsequently evaluated. The images may be evaluated by a grader who may be ophthalmologist, a general practitioner, or a person without or hardly any medical background. The grader evaluates the image of the eye by searching for typical patterns related to specific complications due to diabetes.